A conventional calorie measurement method calculates calories of food based on the amount of protein, fat, and carbohydrate per unit, weight of a food and an energy conversion factor corresponding to each component. A known method calculates the amount of protein based on, for example, the amount of nitrogen quantitated with a Kjeldahl method and the conversion factor of nitrogen-protein. Known methods for calculating the amount of fat include, for example, a Soxhlet extraction method, an improved chloroform-methanol extraction method, a Rose-Gottlieb method, or an acid decomposition method. A known method calculates the amount of carbohydrate with a subtraction method. The conventional calorie measurement method requires many processes to calculate calories and is thus complicated.
Patent Document 1 discloses a calorie measurement device that includes a plate on which food is arranged, a light emitter that irradiates a food with near-infrared light, a light receiver that receives the light reflected by the food, an operation button that starts calorie measurement, and the like. The measurement device calculates the absorbance of the food based on the light received by the light receiver and calculates the calories of the food based on the calculated absorbance.
Such a measurement device allows a user to know the calories of the food just by arranging the food subject to measurement on a plate and operating an operation button to perform measurement. This reduces the burden on the user as compared to the conventional calorie measurement method.